Mutually exclusive stop switch mechanism



1963 D. J. CAMPBELL ETAL 3,106,613

MUTUALLY EXCLUSIVE STOP SWITCH MECHANISM Filed Jan.'25, 1960 mm" W I I II l I l l I INVENTORS. flaw/up J- (AM/ 8521. Dow/11.0 W 62625017,

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United States Patent Office 3,106,618 Patented Oct. 8, 1963 3,106,618MUTUALLY EXCLUSIVE STOP SWITCH MECHANISM Donald J. Campbell, Cincinnati,Donald W. Elbrecht,

Milford, and William L. Fritz, Cincinnati, Ohio, assignors to TheBaldwin Piano Company, Cincinnati,

Ohio, a corporation of ()hio Filed Jan. 25, 1960, Ser. No. 4,273 6Claims. (Cl. 200) This invention has to do with switch mechanismsemploying a plurality of means to be selectively actuated by anoperator, where the arrangement is such that the movement of any one ofthe means, say, to the on position will result in a return of the othermeans in the group to the off position, i.e., a multiple switch devicein which the manually actuated elements are mutually exclusive in theiroperation.

Mutually exclusive switch mechanisms have heretofore been employed invarious electric fields, such as the field of telephony where in generalthe manually actuable means are plungers, and where the actuation of anyone plunger in a group results in the release of all of the otherplungers, which are then returned to non-actuated position by springs orthe like. The devices heretofore produced are not, however, applicableto the present problem; and in most instances they suffer from theadditional defect of being impositive in action so that an inadvertentsimultaneous actuation of two or more plungers may result in thesimultaneous actuation of a plurality of switch mechanisms with whichthey are connected.

In electrical musical instruments the control of voices is usuallyaccomplished by the actuation of tabs or tablets which are pivoted withrespect to a voicing panel, and are actuated by rocking them about theirpivots alternately to oil and on positions, there being some type ofdead-center mechanism to maintain the positions of the tablets sorocked. In the circuitry of electric organs many of the stop tabs arearranged to control voicing circuits which are additive with respect tothe output of the instrument, so that the stop tabs are for the mostpart made to be independent of each other. Thus the operator may employa plurality of voices simultaneously in the output of the instrument.Nevertheless, there are instances in which it is advantageous to providefor the mutually exclusive operation of small groups of stop tablets, orwhere such provision would permit the use of simplified circuitry. Oneinstance may be the provision of stop tabs to effect a combination ofparticular voices, where, as to each such combination, the desiredeffect is obtained only if other stop tabs in the same group are notactuated. Again, in an instrument provided with means for the obtainingof so called percussive efiects, a small number of stop tabs may bearranged to control the rate of tonal decay. Yet another instance mayinvolve the provision of a small number of mutually exclusive tabs tocontrol the rate or amplitude of a vibrato effect.

It is a general object of the invention to provide mutually exclusivemechanism well adapted for use with rocking stop tabs.

It is an object of the invention to provide a mutually exclusivemechanism operated by rocking stop tabs, wherein the movement of one tabto the on position will positively move the other tabs in the group tothe off position.

It is an object of the invention to provide mutually exclusive meansarranged for operation by stop tabs which means is flexible andessentially unlimited as to the number of electrical switch mechanismswhich may be actuated by the depression of any one tab.

It is an object of the invention to provide mutually exclusive means foractuation by stop tabs, which means do not preclude the operation of thesame switch by more than one of the stop tabs in the group. Thisprovision makes possible the securing of the effects of differentarrangements of circuit elements, some of which may be the same for twoor more of the arrangements.

These and other objects of the invention which will be set forthhereinafter or will be apparent to one skilled in the art upon readingthese specifications, are accomplished by that structure and arrangementof parts of which an exemplary embodiment will hereinafter be described.While the description will relate to the stop tabs and associatedmechanism in an electrical musical instrument, it will be understoodthat the principles of the invention are applicable to any circuitrywhich may to advantage be operated by rocking members or tablets.Reference is made to the accompanying drawings wherein:

FIG. 1 is a face view of a portion of the voicing panel of an electricalmusical instrument, showing a series of stop tabs the action of which isto be made mutually exclusive.

FIG. 2 is a rear view of the apparatus.

FIG. 3 is a vertical sectional view taken along the section line 33 ofFIG. 2.

Referring first to FIG. 1, the index numeral 1 indicates the face of avoicing panel which may be of wood, metal, plastic or other substance inkeeping with the style of the console of the musical instrument. Threestop tabs, marked respectively 2, 4 and 5 are shown as mounted on thepanel so as to have a rocking motion. In ordinary practice, the stoptabs will have spaced legs extending through a perforation in the panel.Thus, as shown in FIG. 2 the tab 5 will have legs 6 and 7, the tab 4will have legs 8 and 9, and the tab 2 will have legs 10 and 11. In FIG.3, the tab 4 is shown in section, with the leg 9 extending through theperforation 12 in the voicing panel. The inner ends of the legs of eachof the stop tabs are connected together by rods shown at 13, 14, and 15.In the particular construction, the tabs" are mounted on a commonpivoting rod 16 which passes through perforations in the legs near thestop tab body, and engages at its ends in supports 17 and 18 on the faceof the voicing panel.

The voicing panel is provided on its rear side with an angle member 19which bears a plate 20 lying at an angle to the voicing panel. Springwire members 21, 22 and 23 are attached to the panel 20 as shown. Theirfree ends are bent to form humps which bear respectively against therods 13, 14 and 15 of the stop tabs. It will be evident from the dottedline showing in FIG. 3 that as any stop tab moves from one position tothe other, its rod 13, 14 or 15 will depress one of the spring elements21, 22 or 23, riding past dead-center to a biased position on theopposite side of the hump thereof. Felt strips 24 and 25 or pieces ofother suitable deadening material may be cemented to the voicing panel 1in the positions shown in FIG. 3 so that the operation of the severalstop tabs will be noiseless.

The voicing panel 1 will, in usual constructions, extend across thefront of the instrument console, and may bear numerous independentlyoperable stop tabs for individual voices, as well as other controlmechanism including an off-on switch for the power supply to theinstrument, and any graduated control devices which may be provided. Inelaborated instruments there may be sets of independently operable stoptabs for the great organ manual, for the swell organ manual, and for thepedal clavier. It goes without saying that the voicing panel, ifdesired, may support two or more of the mutually exclusive assembliesdescribed herein.

In order to accomplish the purposes of this invention, each of the stoptabs in the mutually exclusive assembly is arranged to operate a barhaving a reciprocatory motion in a direction generally parallel to theplane of the voicing panel 1. These reciprocatory bars are indicated at26, 27 and 28, and as most clearly shown in FIG. 3, the upper ends ofthe bars are journaled in holes in an angle bracket 29 attached to thevoicing panel, while the lower ends of the bars are provided withangular extensions 30, the free ends of which have a pivotal connectionrespectively with the rods 13, 14 and 15. Thus a rocking of the stoptabs will cause a reciprocation of the bars in the direction shown byarrows in FIG. 3.

The bars are provided selectively with certain extensions on the sidetoward the voicing panel. In FIG. 3 such extensions are shown at 31, 32and 33. A series of bail-like members, formed of wire or rod stock, havetheir out-turned ends journaled in bracket members 39 and 40 on thevoicing panel. The bail-like members are indicated respectively at 34,35, 36, 37 and 38. Any number of these bail-like elements may beprovided in any given assembly, the length of the bars 26, 27 and 28being increased or diminished as may be required. It will be noted inFIG. 3 that the extensions 31, 32 and 33 are arranged to rockrespectively the bail-like members 38, 36 and 34. Movement of the bar 27in FIG. 3 will not result in any rocking of the bail-like elements 37and 35. The other bars, 26 and 28 in the assembly, will have otherprojections extending toward the voicing panel and arranged to rock oneor more of the bail-like elements. Although two or more of the bars 26,27 or 28 may be arranged to rock one or more of the same baillikeelements, the total arrangement as respects each such bar will bedifferent. Thus, the actuation of any one stop tab will result in therocking of a different arrangement and usually, though not necessarily,a different number of the bail-like elements.

The bail-like elements are each arranged to operate one or more switchmechanisms. These switch mechanisms may take various forms within thespirit of the invention. Preferably the switches are of the jack-switchtype in the sense that they embody members extending in the same generaldirection, having a mounting at one end in which the several members areinsulated from each other and are provided with means whereby electricalconnections may be made to them, the members at their outer or free endsbeing so arranged that the movement of one of them will bring two ormore into or out of electrical contact. By way of an exemplary showing,reference is made to FIG. 2 wherein an insulative panel 41 is shownmounted on a bracket 42. A wire member 43 is mounted at one end on thepanel, and, passing through the panel is provided with means for makingan electrical connection thereto as at 44. The wire '43 is elongated soas to reach to the bail-like member 38, and has a bent end which ishooked over that member. A second wire member 45 is also mounted withrespect to the panel and provided with means (not shown) for effectingan electrical connection to a suitable circuit. The outer end of thewire 45 is shown in this particular instance as bent in such a way as tohave a portion lying beneath the wire 43 and making electrical contactwith the wire 43 when it is in the position shown. It will be evidentfrom FIG. 2 that if the bail 38 is rocked upwardly, the wire 43 will bebrought out of contact with the wire 45 and the electrical connectionbroken between them. It will be evident to that skilled worker in theart that other arrangements may be effected in which a similar movementof the wire 43 may be caused to make one or more circuits instead ofbreak a circuit, and that in still other arrangements one circuit may bemade as another circuit is broken. Very satisfactory switches may bemade by the use of spring wire which has been plated with some highlyconductive metal that is strongly resistant to oxidation.

It will also be evident that wherever desired the baillike elements suchas 38 may be caused to operate more than one switch each.

To the bracket 29 there are attached certain depending supports 46, 47,48, preferably in an adjustable fashion. To this end, the supports areslotted as shown and held to an upturned portion 29a of the bracket 29by means of screws 49. Bosses 50 also formed on the part 29a also engagein the slots of the supports 46, 47 and 48 so that these supports arekept in vertical alignment although adjustable as to effective height.Rocker arm members 51, 52 and 53, pivoted to the lower ends of thesupports as shown may also be of flexible construction, so thatactuation of two stop tabs simultaneously will not cause excessivestresses therein. The bars 26, 27 and 28 are formed on their rear edgeswith protuberance-s adapted to contact and rock the arms or to be movedby the arms as will be hereinafter explained. In FIG. 2 the bar 26 isshown as having protuberances 54 and 55 related respectively to therocker arms 51 and 52. If the bar 26 is moved vertically as by actuationof its stop tab, it will be evident that the protuberances 54 and 55will swing the arms 51 and 52 in a clockwise direction as viewed in FIG.2. Should the bar 27 be in the upper position at the time of theaforesaid upward movement of the bar 26 it will be moved downwardlybecause the right-hand end of the swinging arm 52 will engage theprotuberance 56 on the bar 27. Similarly if the bar 28 were in an upperposition when bar 26 is moved upwardly as described, a protuberance 57on bar 28 will be engaged by the rocker arm 51, and the bar 28 will bemoved downwardly. The arrangement is such that only one of the bars 26,27 or 28 can occupy the upper or on position at any one time, and thatmovement of any one of the bars (by means of its stop tab) to the upperposition will result in a movement of either of the other bars to thelower position if they are not already occupying that position. Forexample if the bar 28 were moved upwardly to rock arm 51 in acounterclockwise direction by rneans of the protuberance 57, the bar 26would be swung to the lower position, if it had previously beenoccupying the higher position, by means of the protuberance 54.Similarly the protuberance 58 on bar 23 will swing the arm 53 in acounterclockwise direction, lowering bar 27 by means of protuberance 59if that bar happened to be in the upper position. However, thearrangement is such that while only one bar may occupy the on positionat any one time, all three bars may occupy the off position at the sametime if their respective stop tabs are moved to the off position.

As more clearly shown in FIG. 3 the protuberances on the rear sides ofthe bars 26, 27 and 28, as well as the forward projections on the frontedge of the bars are preferably provided with tubular elements 60 ofsome eifective sound deadening material such as rubber or felt, so thatthe operation of the structure becomes noiseless.

It will be evident to the skilled worker in the art that the structuredisclosed herein may be modified to take care of a greater number ofstop tabs and a correspondingly greater number of the bars such as 26,27 and 28. In order to make the operation of the several bars mutuallyexclusive as hereinabove described, a greater number of swinging armswill have to be provided if a greater number of bars is employed; but itis necessary only to provide such a number and disposition of swingingarms as to move all other bars to the oif position when one bar is movedto the on position. Likewise the number of bail-like elements 34-38 maybe increased as may be found desirable with an appropriate enlargementof the dimensions of the apparatus behind the panel 1.

However, three stop tabs are usually sufficient to provide pre-set voicecombinations for an electric organ. In a copending application of DonaldJ. Campbell, Serial No. 4,294 filed January 25, 1960, now Patent No.3,063,324

and entitled Pre-Set Combination Stop Means for Electric Org-ans, thereare described certain circuit combinations to which the means of thisinvention are excellently adapted. A commonly desired re-set arrangementwould include a flute combination, a string combination and a full-organcombination although other combinations may be added or substituted ifdesired. The combinations may be restricted to a single manual or adifferent means for setting up pre-selected combinations of voices maybe provided for each manual and the pedal clavier; but it is more usualto provide a single arrangement of stop tabs for combination voices,which arrangement will serve to vary the tonal eitect throughout theentire organ.

In any event, the normal method of arranging for preselected voices, asgenerally set forth in the said copending application, will be toprovide in addition to a normal header in which electric oscillationsmay be collected from various sources or through various filters uponthe actuation of single-voice stop tabs, a plurality of additionalheaders having fixed, high impedance connections to groups of sources orvoicing circuits. The last mentioned header may be referred to aspre-set headers, and the several headers including the normal header maybe so connected through the apparatus of this invention to one or moreoutput systems that, when a pre-set stop tab is actuated the normalheader will be disconnected from the output system and the appropriatepre set header or headers connected thereto and vice versa. In someinstances it is desirable to ground headers when they are disconnectedfrom the output system. This may be readily arranged in the use of theapparatus of this invention by the employment of single pole,double-throw switches to be operated by the bail-like elements 34-38.

Modifications may be made in this invention without departing from thespirit of it. The invention having been described in certain exemplaryembodiments, what is claimed as new and desired to be secured by LettersPatent is:

1. In a mutually exclusive stop switch mechanism a panel, stop tabspivoted for swinging motion with respect to said panel, operating meansin connection with said stop tabs extending through said panel, and barson the opposite side of said panel from said stop tabs, said bars beingarranged to be moved longitudinally by said operating means, means foroperating switches attached to said bars, rocker arms extendingtransversely of said bars and means on said bars for swinging saidrocker arms, there being with respect to each bar at least a rocker armconnecting it with the first one of the other bars and at least a rockerarm connecting it with a second one of said other bars, each bar in thestructure having connection by means of a separate rocker arm with eachother bar so that the move ment of a bar in one longitudinal directionwill result in a movement of all other bars in the opposite direction ifsuch other bars have previously been moved in the first mentioneddirection.

2. The structure claimed in claim 1 wherein said rocker arms are capableof moving said bars in but one direction so that all of said bars maysimultaneously occupy positions which are the result of movement of anyone of said bars in a direction opposite to said last mentioneddirection as determined by the positions of said stop tabs.

3. In a mutually exclusive stop switch mechanism a panel, stop tabspivoted for rocking movement with respect to said panel, operating meansattached to said stop tabs and extending through said panel, a bracketon the side of said panel opposite said stop tabs, said bracket having aportion extending away from said panel, bars attached respectively tosaid operating means at one end, journaled for sliding movement adjacenttheir other ends in the said bracket portion, means in connection withsaid bars for the selective operation of switches, supports attached tosaid bracket portion and extending in general parallelism with saidbars, rocker arms pivoted to said supports, and means on said bars forcontacting and swinging said arms and for producing movement of saidbars when said arms are swung by another bar the interaction betweensaid arms and said means on said bars being such that only one of saidbars may occupy a position which is the result of a longitudinalmovement of said bar in one direction as produced by its respective stoptab, but all bars may occupy simultaneously an opposite position.

4. The structure claimed in claim 3 including spring means engaging theoperating means on said stop tabs and acting as a dead center mechanismto maintain positions of said stop tabs as determined by their rockingmovement.

5. The structure claimed in claim 4 including bail-like switch actuatingmeans having end portions pivoted in extensions on said bracket, theswitch actuating means on said bars comprising projections differing inposition as to each of said bars and serving to rock said bail-likemembers selectively when said bars are moved.

6. In a mutually exclusive stop switch mechanism a series of at leastthree bars mounted for longitudinal movement under the influence ofmanually actuable stop devices, and a series of rocker arms extendingtransversely of said bars, there being with respect to each bar at leasta rocker arm connecting it with a first one of the other bars and atleast a rocker arm connecting it with a second one of said other bars,each bar in the structure having connection by means of a separaterocker arm with each other bar, said bars having means for engaging saidrocker arms whereby movement of said rocker arms will move said bars inone direction and movement of said bars in the opposite direction willmove said rocker arms, whereby only one of said bars may occupy onelongitudinal position at any one time, there being another longitudinalposition which all bars may occupy at the same time, and means inconnection with said bars operating switch means.

References Cited in the file of this patent UNITED STATES PATENTS1,956,350 Hammond Apr. 24, 1934 2,595,083 Kilgen Apr. 29, 1952 2,887,551Detwiler May 19, 1959

1. IN A MUTUALLY EXCLUSIVE STOP SWITCH MECHANISM A PANEL, STOP TABSPIVOTED FOR SWINGING MOTION WITH RESPECT TO SAID PANEL, OPERATING MEANSIN CONNECTION WITH SAID STOP TABS EXTENDING THROUGH SAID PANEL, AND BARSON THE OPPOSITE SIDE OF SAID PANEL FROM SAID STOP TABS, SAID BARS BEINGARRANGED TO BE MOVED LONGITUDINALLY BY SAID OPERATING MEANS, MEANS FOROPERATING SWITCHES ATTACHED TO SAID BARS, ROCKER ARMS EXTENDINGTRANSVERSELY OF SAID BARS AND MEANS ON SAID BARS FOR SWINGING SAIDROCKER ARMS, THERE BEING WITH RESPECT TO EACH BAR AT LEAST A ROCKER ARMCONNECTING IT WITH THE FIRST ONE OF THE OTHER BARS AND AT LEAST A ROCKERARM CONNECTING IT WITH A SECOND ONE OF SAID OTHER BARS EACH BAR IN THESTRUCTURE HAVING CONNECTION BY MEANS OF A SEPARATE ROCKER ARM WITH EACHOTHER BAR SO THAT THE MOVEMENT OF A BAR IN ONE LONGITUDINAL DIRECTIONWILL RESULT IN A MOVEMENT OF ALL OTHER BARS IN THE OPPOSITE DIRECTION IFSUCH OTHER BARS HAVE PREVIOUSLY BEEN MOVED IN THE FIRST MENTIONEDDIRECTION.